Dynamic link selection

ABSTRACT

A method for dynamic link selection that comprises providing at least two wireless links between one or more network nodes and a wireless device. The at least two wireless links associated with at least two different radio access technologies. The method additionally includes obtaining control data to be sent to a first network node of the one or more network nodes. The control data is associated with a first radio access technology. The method additionally includes selecting one or more wireless links from among the at least two wireless links. The one or more links selected based on a first selection parameter. The one or more selected wireless links are to be used for the transmission of the control data to the first network node. The one or more selected wireless links comprise at least a first wireless link associated with a second radio access technology. The method further includes transmitting the control data associated with the first radio access technology to the first network node via at least the first wireless link associated with the second radio access technology. The method also includes obtaining the control data at the first network node and determining whether the received control data is duplicated control data.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/325,165, filed Feb. 12, 2019, which is a 371 of InternationalApplication No. PCT/IB2017/001137, filed Aug. 14, 2017, which claimspriority to U.S. Application No. 62/476,302, filed Mar. 24, 2017, andclaims priority to U.S. Application No. 62/374,152, filed Aug. 12, 2016,the disclosures of which are fully incorporated herein by reference.

TECHNICAL FIELD

Embodiments presented herein relate to dynamic link selection, and inparticular to methods, network nodes, wireless devices, computerprograms, or computer program products for selecting one or morewireless links to use to transmit data.

BACKGROUND

Overall requirements for the Next Generation (NG) architecture forwireless networks (see TR 23.799, Study on Architecture for NextGeneration) and, more specifically the NG Access Technology (see TR38.913, Study on Scenarios and Requirements for Next Generation AccessTechnologies) will impact the design of 5G (also referred to as NewRadio (NR)) (see RP-160671, New SID Proposal: Study on New Radio AccessTechnology, DoCoMo) from mobility to control plane design andmechanisms.

In Long Term Evolution (LTE), it was discussed during the DualConnectivity (DC) study item to support sending Radio Resource Control(RRC) messages via both Master Evolved Node B (eNB) (MeNB) and SecondaryeNB (SeNB), which is referred to as “RRC diversity”. In these studies,it was shown that RRC diversity could provide notable gains in case ofmulti-layer (inter-frequency) DC scenarios (see 3GPP TR 36.842, Study onSmall Cell enhancements for E-UTRA and E-UTRAN; Higher layer aspects(Release 12), December 1113). However, due to lack of time, RRCdiversity was down prioritized and left out of the work item.

In NR, the requirements (see R2-163993, NR/LTE tight-interworking: CPrequirements on Mobility and Dual Connectivity, Ericsson, RAN2 #94,23-27 May 1216) set on Ultra-Reliable and Low Latency Communications(URLLC) services suggest a revisit of RRC diversity once again formulti-layer deployments. In this context, the applicability of a widerset of numerologies and larger range of frequencies could make RRCdiversity an even more desirable feature than before. This is because,for instance, while a lower-frequency LTE layer could provide bettercontrol plane coverage, a higher-frequency NR layer, thanks to itsenvisioned Radio Access Technology (RAT) design, may provide fasterdelivery of a control plane message. In addition, RRC diversity canparticularly help improve mobility robustness as discussed within theearlier LTE studies.

U.S. patent application Ser. No. 15/035,729 “DISCARDING A DUPLICATEPROTOCOL DATA UNIT ASSOCIATED WITH A DATA TRANSMISSION VIA A FIRSTSIGNALING RADIO BEARER ORA SECOND SIGNALING RADIO BEARER”, describes thereceiver algorithm for duplicate discard for RRC diversity withsplitting done by the Packet Data Convergence Protocol (PDCP). Itdefines how PDCP Protocol Data Units (PDUs) are duplicated using thesame sequence number X, and in the receiver the sequence number is usedto remove duplications.

RRC diversity is envisioned for both the downlink and uplink to addressthe aforementioned challenges related to URLLC and mobility robustness.However, how dynamic link selection should be realized is still an openquestion.

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the technical field, unless explicitly definedotherwise herein. All references to “a/an/the element, apparatus,component, means, step, etc.” are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methoddisclosed herein do not have to be performed in the exact orderdisclosed, unless explicitly stated.

SUMMARY

An object of embodiments herein is to provide methods, wireless devices,and network nodes that are able to perform dynamic link selection.According to certain embodiments, a method for dynamic link selectioncomprises providing at least two wireless links between one or morenetwork nodes and a wireless device. The at least two wireless links areassociated with at least two different radio access technologies. Themethod additionally includes obtaining control data that is to be sentto a first network node of the one or more network nodes. The controldata is associated with a first radio access technology. The methodfurther includes selecting one or more wireless links from among the atleast two wireless links. The one or more wireless links may be selectedbased on a first selection parameter. The selected one or more wirelesslinks are to be used for the transmission of the control data to thefirst network node. The selected one or more wireless links includes atleast a first wireless link that is associated with a second radioaccess technology. The method also includes transmitting the controldata associated with the first radio access technology to the firstnetwork node via at least the first wireless link associated with thesecond radio access technology. The method additionally includesobtaining the control data at the first network node and determiningwhether the received control data is duplicated control data.

According to some embodiments, a method for dynamic link selectioncomprises obtaining data to be sent to a network node. The methodadditionally includes selecting one or more wireless links to use forthe transmission of the data to be sent to the network node. The one ormore wireless links may be selected from a group of at least twoavailable wireless link that are associated with at least two differentradio access technologies. The method further includes transmitting thedata to the network node via the selected one or more wireless links.

In some embodiments, the data that is to be sent comprises control datafor a first wireless link of the at least two available wireless links.The first wireless link is associated with a first radio accesstechnology. In such embodiments, the method may also includetransmitting the control data to the network node via at least a secondwireless link of the at least two available wireless links. The secondwireless link is associated with a second radio access technology thatis different than the first radio access technology.

In certain embodiments, the method also includes, upon selecting atleast two wireless links from the group of at least two availablewireless links, replicating the data to be transmitted. In suchembodiments, the method may further include transmitting the replicateddata to the network node via the at least two selected wireless linkssuch that the at least two selected wireless links convey the same datavia different radio access technologies. In some instances, the datatransmitted on at least one of the selected wireless links istransmitted to the network node via a second network node.

In some embodiments, selecting one or more wireless links to use for thetransmission of the data comprises evaluating a link quality associatedwith each of the wireless links. In certain embodiments selecting one ormore wireless links to use for the transmission of the data comprisesevaluating buffer status associated with each of the wireless links.

In certain embodiments, the data that is to be sent is control planedata. In particular embodiments, transmitting the data comprises, foreach selected wireless link, forwarding a Packet Data ConvergenceProtocol (PDCP) Protocol Data Unit (PDU) to a respective lower layerlink.

In some embodiments, selecting the one or more wireless links is done ona per PDCP PDU basis. In some embodiments selecting the one or morewireless links is done on a per Radio Link Control (RLC) PDU basis. Insome embodiments, the data comprises Radio Resource Control (RRC)messages.

In accordance with particular embodiments, a wireless device for dynamiclink selection comprises processing circuitry. The processing circuitryis configured to obtain data to be sent to a network node. Theprocessing circuitry is further configured to select one or morewireless links to use for the transmission of the data to be sent to thenetwork node. The one or more wireless links are selected from a groupof at least two available wireless links. The at least two availablewireless links are associated with at least two different radio accesstechnologies. The wireless device additionally includes a wirelessinterface that is configured to transmit the data to the network nodevia the selected one or more wireless links. The wireless device furtherincludes a power source configured to provide the wireless device withpower. The wireless device additionally includes a user interface.

In accordance with certain embodiments, a network node for dynamic linkselection comprises a wireless interface that is configured to provideat least a first wireless link for wireless communication with awireless device. The first wireless link is associated with a firstradio access technology. The network node additionally includes a secondinterface configured to obtain control data from the wireless device.The control data is transmitted by the wireless device via a secondwireless link. The second wireless link is associated with a secondradio access technology different than the first radio accesstechnology. The network node additionally includes processing circuitrythat is configured to determine whether the received control data isduplicated control data.

In accordance with some embodiments, a wireless device for dynamic linkselection comprises a processor and computer readable storage media. Thestorage media contains instructions that are executable by theprocessor. When executed the wireless device is operative to obtain datato be sent to a network node. The wireless device is further operativeto select one or more wireless links to use for the transmission of thedata to be sent to the network node. The one or more wireless links areselected from a group of at least two available wireless links. The atleast two available wireless links are associated with at least twodifferent radio access technologies. The wireless device is additionallyoperative to transmit the data to the network node via the selected oneor more wireless links.

In accordance with particular embodiments, a wireless device for dynamiclink selection comprises an obtain unit configured to obtain data to besent to a network node. The wireless device additionally includes aselection unit configured to select one or more wireless links to usefor the transmission of the data to be sent to the network node. The oneor more wireless links are selected from a group of at least twoavailable wireless links. The at least two available wireless links areassociated with at least two different radio access technologies. Thewireless device additionally includes a transmit unit configured totransmit the data to the network node via the selected one or morewireless links.

Advantageously, one or more embodiments provided herein improve radioresource (e.g., spectrum, power, etc.) utilization and robustness inwireless networks. In some embodiments, dynamic link selection canimprove the use of the resources belonging to multiple different radioaccess technologies (RATs) by adding in the selection for whether tosend the control plane (SRB) data on multiple links or one of the links.

It is to be noted that any feature of any of the above embodiments maybe applied to any other embodiment, wherever appropriate. Likewise, anyadvantage of any of the embodiments may apply to the other embodiments,and vice versa. Other objectives, features and advantages of theenclosed embodiments will be apparent from the following detaileddisclosure, attached claims, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Particular embodiments are now described, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a schematic block diagram illustrating a wireless networkaccording to particular embodiments;

FIG. 2 is a schematic block diagram illustrating a user equipmentaccording to particular embodiments;

FIG. 3 is a block diagram illustrating RRC diversity according toparticular embodiments;

FIG. 4 is a block diagram illustrating lower layer feedback according toparticular embodiments;

FIG. 5 is a block diagram illustrating an RLC split according toparticular embodiments;

FIG. 6 is a flow chart illustrating a method for dynamic link selectionaccording to particular embodiments; and

FIG. 7 is a block diagram illustrating the functional units used indynamic link selection, according to particular embodiments.

DETAILED DESCRIPTION

Some of the embodiments contemplated by the claims will now be describedmore fully hereinafter with reference to the accompanying drawings.Other embodiments, however, are contained within the scope of the claimsand the claims should not be construed as limited to only theembodiments set forth herein; rather, these embodiments are provided byway of example to help convey the scope of the inventive concept tothose skilled in the art. Like numbers refer to like elements throughoutthe description.

FIG. 1 is a schematic block diagram illustrating a wireless networkaccording to particular embodiments. Although the embodiments describedherein may be implemented in any appropriate type of system using anysuitable type and number of components, particular embodiments may beimplemented in a wireless network such as the example wirelesscommunication network illustrated in FIG. 1. In the example embodimentof FIG. 1, the wireless communication network provides communication andother types of wireless services to one or more wireless devices. In theillustrated embodiment, the wireless communication network includes oneor more instances of network nodes that facilitate the wireless devices'access to and/or use of the services provided by the wirelesscommunication network. The wireless communication network may furtherinclude any additional elements suitable to support communicationbetween wireless devices or between a wireless device and anothercommunication device, such as a landline telephone or a remote server.

The wireless communication network may represent any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other type of system. In particular embodiments, the wirelesscommunication network may be configured to operate according to specificstandards or other types of predefined rules or procedures. Thus,particular embodiments of the wireless communication network mayimplement communication standards, such as Global System for MobileCommunications (GSM), Universal Mobile Telecommunications System (UMTS),Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, or 5Gstandards; wireless local area network (WLAN) standards, such as theIEEE 802.11 standards; and/or any other appropriate wirelesscommunication standard, such as the Worldwide Interoperability forMicrowave Access (WiMax), Bluetooth, and/or ZigBee standards. Thesevarious disparate standards may be referred to herein generally as RadioAccess Technologies (RATs).

Network 150 may comprise one or more IP networks, public switchedtelephone networks (PSTNs), packet data networks, optical networks, widearea networks (WANs), local area networks (LANs), wireless local areanetworks (WLANs), wired networks, wireless networks, metropolitan areanetworks, and other networks to enable communication between devices.

Illustrated in FIG. 1 is a more detailed view of network node 120 andwireless device (WD) 110, in accordance with a particular embodiment.For simplicity, FIG. 1 only depicts network 150, network nodes 120 and120 a, and WD 110. These components may work together in order toprovide network node and/or wireless device functionality, such asproviding wireless connections, or links, in a wireless network. Thesecomponents may also work to provide dynamic link selection. In differentembodiments, the wireless network may comprise any number of wired orwireless networks, network nodes, base stations, controllers, wirelessdevices, relay stations, and/or any other components that may facilitateor participate in the communication of data and/or signals whether viawired or wireless connections.

Network node 120 may include any equipment capable, configured, arrangedand/or operable to communicate directly or indirectly with a wirelessdevice and/or with other equipment in the wireless communication networkthat enable and/or provide wireless access or services via wirelesslinks to WD 110. For example, network node 120 may be an access point(AP), in particular a radio access point. Network node 120 may representbase stations (BSs), such as radio base stations. Particular examples ofradio base stations include Node Bs, and evolved Node Bs (eNBs). Ingeneral, base stations may be categorized based on the amount ofcoverage they provide (or, stated differently, their transmit powerlevel) and may then also be referred to as femto base stations, picobase stations, micro base stations, or macro base stations. Network node120 may also include one or more (or all) parts of a distributed radiobase station such as centralized digital units and/or remote radio units(RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remoteradio units may or may not be integrated with an antenna as an antennaintegrated radio. Parts of a distributed radio base station may also bereferred to as nodes in a distributed antenna system (DAS). As aparticular non-limiting example, a base station may be a relay node or arelay donor node controlling a relay.

In yet further examples, network node 120 may include multi-standardradio (MSR) radio equipment such as MSR BSs, network controllers such asradio network controllers (RNCs) or base station controllers (BSCs),base transceiver stations (BTSs), transmission points, transmissionnodes, Multi-cell/multicast Coordination Entities (MCEs), core networknodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioningnodes (e.g., E-SMLCs), and/or MDTs.

In FIG. 1, Network node 120 comprises interface 121, processor 122,storage 123, and antenna 121 a. These components are depicted as singleboxes located within a single larger box. In practice however, a networknode may comprise multiple different physical components that make up asingle illustrated component (e.g., interface 121 may comprise terminalsfor coupling wires for a wired connection and a radio transceiver for awireless connection). As another example, network node 120 may be avirtual network node in which multiple different physically separatecomponents interact to provide the functionality of network node 120(e.g., processor 122 may comprise three separate processors located inthree separate enclosures, where each processor is responsible for adifferent function for a particular instance of network node 120).Similarly, network node 120 may be composed of multiple physicallyseparate components (e.g., a NodeB component and an RNC component, a BTScomponent and a BSC component, etc.), which may each have their ownrespective processor, storage, and interface components. In certainscenarios in which network node 120 comprises multiple separatecomponents (e.g., BTS and BSC components), one or more of the separatecomponents may be shared among several network nodes. For example, asingle RNC may control multiple NodeB's. In such a scenario, each uniqueNodeB and BSC pair, may be considered a separate network node. In someembodiments, network node 120 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate storage 123 for the different RATs)and some components may be reused (e.g., the same antenna 121 a may beshared by the RATs).

Processor 122 may be a combination of one or more of a microprocessor,controller, microcontroller, central processing unit, digital signalprocessor, application specific integrated circuit, field programmablegate array, or any other suitable computing device, resource, orcombination of hardware, software and/or encoded logic operable toprovide, either alone or in conjunction with other network node 120components, such as storage 123, network node 120 functionality. Forexample, processor 122 may execute instructions stored in storage 123.Such functionality may include providing various wireless featuresdiscussed herein to a wireless device, such as WD 110, including any ofthe features or benefits disclosed herein.

Storage 123 may comprise any form of volatile or non-volatile computerreadable memory including, without limitation, persistent storage, solidstate memory, remotely mounted memory, magnetic media, optical media,random access memory (RAM), read-only memory (ROM), removable media, orany other suitable local or remote memory component. Storage 123 maystore any suitable instructions, data or information, including softwareand encoded logic, utilized by network node 120. Storage 123 may be usedto store any calculations made by processor 122 and/or any data receivedvia interface 121.

Network node 120 also comprises interface 121 which may be used in thewired or wireless communication of signalling and/or data betweennetwork node 120, network 150, and/or WD 110. For example, interface 121may perform any formatting, coding, or translating that may be needed toallow network node 120 to send and receive data from network 150 over awired connection. Interface 121 may also include a radio transmitter,receiver and/or transceiver that may be coupled to or a part of antenna121 a. The radio may receive digital data that is to be sent out toother network nodes or WDs via a wireless connection. The radio mayconvert the digital data into a radio signal having the appropriatechannel and bandwidth parameters. The radio signal may then betransmitted via antenna 121 a to the appropriate recipient (e.g., WD110).

Antenna 121 a may be any type of antenna capable of transmitting andreceiving data and/or signals wirelessly. In some embodiments, antenna121 a may comprise one or more omni-directional, sector or panelantennas operable to transmit/receive radio signals between, forexample, 2 GHz and 66 GHz. An omni-directional antenna may be used totransmit/receive radio signals in any direction, a sector antenna may beused to transmit/receive radio signals from devices within a particulararea, and a panel antenna may be a line of sight antenna used totransmit/receive radio signals in a relatively straight line.

WD 110 may represent any device capable, configured, arranged and/oroperable to communicate wirelessly with network nodes and/or anotherwireless device. Communicating wirelessly may involve transmittingand/or receiving wireless signals using electromagnetic signals, radiowaves, infrared signals, and/or other types of signals suitable forconveying information through air. In particular embodiments, WD 110 maybe configured to transmit and/or receive information without directhuman interaction. For instance, WD 110 may be designed to transmitinformation to a network on a predetermined schedule, when triggered byan internal or external event, or in response to requests from thenetwork. Generally, WD 110 may represent any device capable of,configured for, arranged for, and/or operable for wirelesscommunication, for example radio communication devices. Examples ofwireless devices include, but are not limited to, user equipment (UE)such as smart phones. Further examples include wireless cameras,wireless-enabled tablet computers, laptop-embedded equipment (LEE),laptop-mounted equipment (LME), USB dongles, and/or wirelesscustomer-premises equipment (CPE).

As one specific example, WD 110 may represent a UE, such as UE 200 ofFIG. 2, configured for communication in accordance with one or morecommunication standards promulgated by the 3^(rd) Generation PartnershipProject (3GPP), such as 3GPP′s GSM, UMTS, LTE, and/or 5 G standards. Asused herein, a “user equipment” or “UE” may not necessarily have a“user” in the sense of a human user who owns and/or operates therelevant device. Instead, a UE may represent a device that is intendedfor sale to, or operation by, a human user but that may not initially beassociated with a specific human user. The wireless device may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, and may in this case be referred toas a D2D communication device.

As yet another specific example, in an Internet of Things (IOT)scenario, WD 110 may represent a machine or other device that performsmonitoring and/or measurements, and transmits the results of suchmonitoring and/or measurements to another wireless device and/or anetwork node. WD 110 may in this case be a machine-to-machine (M2M)device, which may in a 3GPP context be referred to as a machine-typecommunication (MTC) device. As one particular example, WD 110 may be aUE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g., refrigerators, televisions, personalwearables such as watches etc.). In other scenarios, WD 110 mayrepresent a vehicle or other equipment that is capable of monitoringand/or reporting on its operational status or other functions associatedwith its operation.

A wireless device as described above may represent the endpoint of awireless connection, in which case the device may be referred to as awireless terminal. Furthermore, a wireless device as described above maybe mobile, in which case it may also be referred to as a mobile deviceor a mobile terminal.

As depicted in FIG. 1, WD 110 may be any type of wireless endpoint,mobile station, mobile phone, wireless local loop phone, smartphone,user equipment, desktop computer, PDA, cell phone, tablet, laptop, VoIPphone or handset, which is able to wirelessly send and receive dataand/or signals to and from a network node, such as network node 120and/or other WDs. WD 110 comprises interface 111, processor 112, storage113, and antenna 111 a. The components of WD 110 are depicted as singleboxes located within a single larger box, however in practice a wirelessdevice may comprises multiple different physical components that make upa single illustrated component (e.g., storage 113 may comprise multiplediscrete microchips, each microchip representing a portion of the totalstorage capacity).

Processor 112 may be a combination of one or more of a microprocessor,controller, microcontroller, central processing unit, digital signalprocessor, application specific integrated circuit, field programmablegate array, or any other suitable computing device, resource, orcombination of hardware, software and/or encoded logic operable toprovide, either alone or in combination with other WD 110 components,such as storage 113, WD 110 functionality. Such functionality mayinclude providing various wireless features discussed herein, includingany of the features or benefits disclosed herein.

Storage 113 may be any form of volatile or non-volatile memoryincluding, without limitation, persistent storage, solid state memory,remotely mounted memory, magnetic media, optical media, random accessmemory (RAM), read-only memory (ROM), removable media, or any othersuitable local or remote memory component. Storage 113 may store anysuitable data, instructions, or information, including software andencoded logic, utilized by WD 110. Storage 113 may be used to store anycalculations made by processor 112 and/or any data received viainterface 111.

Interface 111 may be used in the wireless communication of signallingand/or data between WD 110 and network node 120. For example, interface111 may perform any formatting, coding, or translating that may beneeded to allow WD 110 to send and receive data from network node 120over a wireless connection. Interface 111 may also include a radiotransmitter and/or receiver that may be coupled to or a part of antenna111 a. The radio may receive digital data that is to be sent out tonetwork node 121 via a wireless connection. The radio may convert thedigital data into a radio signal having the appropriate channel andbandwidth parameters. The radio signal may then be transmitted viaantenna 111 a to network node 120. Interface 111 may also include a userinterface comprising an input interface (such as input interface 220 andan output interface such as output interface 225).

Antenna 111 a may be any type of antenna capable of transmitting andreceiving data and/or signals wirelessly. In some embodiments, antenna111 a may comprise one or more omni-directional, sector or panelantennas operable to transmit/receive radio signals between 2 GHz and 66GHz. For simplicity, antenna 111 a may be considered a part of interface111 to the extent that a wireless signal is being used.

The various components of the various devices illustrated FIG. 1 may beused in providing dynamic link selection. Dynamic link selection mayalso be performed by devices and/or components not specificallyillustrated herein but which are known to provide similar features orcapabilities as discussed herein. Below, the following examples andexplanations of the features, benefits and components will mostly bedescribed with respect to how dynamic link selection could be made forcontrol plane (CP) transmissions. However, similar features and benefitsmay be applicable to user plane (UP) transmissions as well. Indescribing the illustrated components and how they may be used indifferent embodiments to provide dynamic link selection it may beassumed that wireless device 110 has established wireless link 130 withnetwork node 120 and wireless link 140 with network node 120 a. It mayfurther be assumed that these two wireless links are based on differentradio access technologies. For example, wireless link 130 may be basedon LTE and wireless link 140 may be based on WiMax. As another example,wireless link 130 may be based on NR and wireless link 140 may be basedon WiFi. Any of a variety of other combinations may be possibledepending on the capabilities and features of the wireless interface ofwireless device 110.

In one embodiment, processor 112 of wireless device 110 may compriseprocessing circuitry. The processing circuitry may obtain data that isto be sent via interface 111 to network node 120. The data that is to besent can take a variety of forms and may be obtained through differentsources. For example, in some embodiments the data may be control data(e.g., control plane data, radio resource control (RRC) data, etc.)generated by processor 112. In another example, the data may be userdata (e.g., user plane data such as data entered by a user, datagenerated by one or more programs being executed by wireless device 110etc.) received through a user interface of wireless device 110 or someprogram or application be run by processor 112.

Processor 112 may then select wireless link 130 and/or 140 to use totransmit the data to network node 120. Processor 112 may examine channelconditions, buffer status, and/or link quality of the possible wirelesslinks 130 and 140 which may be used for transmission of the data. Linkselection may be based on the absolute values or the relative values.For example, in some scenarios the channel conditions and/or linkquality for wireless links 130 and 140 may be such that processor 112may select wireless link 140 to send control data to base station 120even though wireless link 140 is associated with a different radioaccess technology than what is provided by base station 120. In someinstances, processor 112 may select multiple wireless links to use tosend the data. For example, processor 112 may select both wireless links130 and 140 to use to send the data to network node 120.

In some embodiments, processor 112 may use lower layer feedback messagesto evaluate link quality. This can be seen in FIG. 4. For example, ifacknowledgement message 420 is received on wireless link 410 for PDU 1,then processor 112 may determine that wireless link 430 is not asdesirable as wireless link 410, even though wireless link 430 isassociated with the master cell group (e.g., the cell with which thedata is associated). In some embodiments, if the lower layer (RLC/MAC)indicates a successful delivery of PDCP PDU(s), then processor 112 of WD110 may, at the PDCP level, discard the PDU without forwarding it to thelower layers or waiting for a second indication from another link.

If multiple wireless links are selected, processor 112 may need toreplicate the processing of the data so that it is suitable fortransmission via the multiple wireless links. For example, processor mayduplicate the data. As another example, processor 112 may replicate thepackaging of the data (e.g., formatting, headers, packetization, etc.).In replicating the packaging of the data, the process is repeatedalthough the actual information may change. That is, processor 112 maycreate a second header, but that header may contain a different address.Processor 112 may select the wireless links on which to send the data ona per Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU)basis. That is, processor 112 may select wireless link 130 to send afirst PDCP PDU and then select wireless link 140 to send the immediatelysubsequent PDCP PDU. In some embodiments, processor 112 may select thewireless links to use to send the data on a per Radio Link Control (RLC)PDU basis.

Interface 111 may comprise a wireless interface that is able to send thedata via the selected wireless link. For example, if processor 112selects wireless link 140 to send the data to network node 120, andwireless link 140 is an LTE link, then interface 111 may comprise theradio, transmitter, or other such interface components needed totransmit an LTE message via wireless link 140. As can be seen in FIG. 1,in order for the data sent via wireless link 140 to get to network node120 it must first be received by network node 120 a and then forwardedon to network node 120.

Interface 111 may comprise a wireless interface that is able to receivedata via one or both of wireless links 130 and 140. This can be seen inbetter detail in FIGS. 3 and 5 wherein FIG. 3 is a block diagramillustrating RRC diversity at the PDCP level and FIG. 5 is a blockdiagram illustrating RRC diversity at the RLC level. With respect toFIG. 3, RRC diversity is realized based on a PDCP level split. When dataintended for WD 110 is received by the primary or master network node310, and RRC diversity is active at the PDCP level 311, master networknode 310 may send the data to secondary network node 320 via inter-nodeinterface X2* where it is received and processed at RLC 321 of secondarynetwork node 320. As the data is forwarded to lower layers in the twonetwork nodes, it eventually is transmitted over wireless links 130 and140 enabling interface 111 to receive the data. In some scenarios, thedata initially received by master network node 310 may only betransmitted by secondary network node 320. The selection of one, or theother, or both wireless links may be made on a PDU basis (RRC PDU orSDU, or PDCP PDU). With respect to FIG. 5, master network node 510receives the data, but in this scenario PDCP 511 forwards the data toRLC 512 and then the data is sent to RLC 522 via inter-node interfaceX2*. In FIG. 5, RRC diversity architecture when RLC split is used, RLC512 with solid lines denotes the master RLC where the RRCdiversity/split is realized. RLC 522 with dashed lines refers to thesecondary or slave RLC which handles the basic RLC functions atsecondary network node 520.

In FIGS. 3 and 5, inter-node interface X2* represents the inter-nodeinterface between master network node 310/510 and secondary network node320/520. Inter-node interface X2* may be used to send and receivemessages, information, and/or other data between the network nodes. Forexample, if interface 121 of network node 120 receives data from WD 110that is intended for network node 120 a, interface 121 may forward thedata on to network node 120 a via inter-node interface X2*. Inter-nodeinterface X2* may represent a wired or wireless connection that mayinvolve any number of hops between the two base stations.

In certain embodiments, processor 112 and storage 113 may be used to mapPDUs to the lower layer links in the context of RRC diversity. In someembodiments, the control plane architecture of signalling radio bearer(SRB) level split at the PDCP protocol layer may be adopted. In certainembodiments, other protocol layers such as RLC (see FIG. 5) or mediumaccess control (MAC) can also enable RRC diversity. The embodimentsdisclosed herein are not limited to the given architecture examples, andthe basic principles can be realized with little impact from theselected architecture option. In some embodiments, before RRC diversitycan be activated, processor 112 and interface 111 may need to configurethe respective wireless links and enable the certain security featuresof the respective RAT. This may occur during the initial connectionsetup or connection re-establishment.

In some embodiments, processor 112 of WD 110 may make link selectiondecisions on a per RRC PDU/SDU basis. For example, processor 112 canmake the decision based on the RRC message type. For example, a HOcommand could be sent on both wireless links 130 and 140 by the lowerlayers.

In another embodiment, processor 112 may make the link selectiondecision on a per PDCP PDU basis. In this case a PDCP entity can makethe decision based on the services provided by lower layers, forinstance, this could be simply an indication of successful delivery ofPDCP PDUs. In some implementations, the service could be simply thedynamic link selection decision itself; or a measurement indication ormeasurement report that can be used for the mapping.

In some of the embodiments, where the link selection decision is made ona per PDCP PDU basis, processor 112 may default to mapping control planedata to both/all configured wireless links. This may provide diversityand improved robustness for the control plane data. In anotherembodiment, such as where RRC diversity is realized by an RLC-levelsplit, dynamic link selection may be made on a per RLC PDU basis or byhigher layers (e.g., PDCP PDU or RRC PDU/SDU basis).

In some embodiments, dynamic link selection could be implementationspecific (e.g., for the downlink) and standardized (e.g., for theuplink). This may improve the predictability of the behaviour of WD 110.This may also allow, for example, for the signal quality and latencyaspects of each link to be taken into account for the rules of dynamiclink selection. In some embodiments, processor 112 may select which linkor links to use based on at least one of a measurement and measurementreport. In certain embodiments, the link selection decision can be madein the transmitter side (network node 120 for downlink (DL) and WD 110for uplink (UL)). Alternatively, network node 120 may control thedecision in both directions by sending commands to transmitting entity.The command can be sent on the physical, MAC, PDCP or RRC layer.

In some embodiments, processor 112 may use measurements for a reverselink to make a link selection. This may be suitable where channelreciprocity can be utilized. For example, processor 112 may performdownlink measurements (e.g., signal strength) for data received fromnetwork node 120. The measurement values may then be used in selectingwhich wireless links interface 111 may use to for uplink datatransmission to network node 120.

In some embodiments, interface 111 may prepare the data fortransmission. Where data is being transmitted via multiple links, thedata may be prepared separately or independently for each wireless linkto be used to transmit the data. For example, for each selected wirelesslink, interface 111 may forward a PDCP PDU to a respective lower layerlink. In doing so, processor 112 and storage 113 may be used toreplicate the data that is being sent to each of the respective lowerlayers.

Interface 121 of network node 120 may receive the data either directlyfrom wireless device 110, via wireless link 130, or indirectly fromnetwork node 120 a. Different components of interface 121 may be useddepending on where the data is received. That is, wireless interfacecomponents may be used to receive the data via wireless link 130, whilea wired interface component may be used to receive the data indirectlyfrom network node 120 a.

Processor 122 may comprise processing circuitry to analyse data receivedby interface 121. For example, because interface 121 may receive datathat wireless device 110 has sent through multiple wireless links,network node 120 may receive duplicate data. Accordingly, processor 122may examine the received data to determine whether it is duplicate data.For example, if interface 121 first receives data from wireless link 130it may determine that it is not duplicate data. Then, if interface 121receives the same data from network node 120 a, processor 122 maydetermine that it is duplicate data. In some embodiments, the duplicatedata may be discarded. In some embodiments, the duplicate data may becombined to avoid having to request a retransmission.

Another form of analysis processor 122 may perform is to determinewhether to keep the data for processing internally or to forward thedata to network node 120 a. That is, because wireless device 110 may usewireless link 130 to send data, such as control data, intended fornetwork node 120 a. Processor 122 may need to determine whether the datareceived via wireless link 130 is for network node 120 or network node120 a. If the received data is for network node 120 a, interface 121 mayprepare and transmit the data towards network node 120 a. Interface 121may use different components to receive the data from wireless device110 and to forward the data towards network node 120 a.

FIG. 2 is a schematic block diagram of a user equipment according toparticular embodiments. User Equipment (UE) 200 is a type of a wirelessdevice. UE 200 includes an antenna 205, radio front-end circuitry 210,processing circuitry 215, input interface 220, output interface 225,computer-readable storage medium 230, and power source 235. Antenna 205may include one or more antennas or antenna arrays, and is configured tosend and/or receive wireless signals, and is connected to radiofront-end circuitry 210. In certain alternative embodiments, UE 200 maynot include antenna 205, and antenna 205 may instead be separate from UE200 and be connectable to UE 200 through an interface or port.

Radio front-end circuitry 210, along with antenna 205, may be consideredpart of an interface, or more specifically a wireless interface. Radiofront-end circuitry 210 may comprise various filters and amplifiers usedin generating or decoding a radio signal. Radio front-end circuitry 210,is connected to antenna 205 and processing circuitry 215. Radiofront-end circuitry 210 is configured to condition signals communicatedbetween antenna 205 and processing circuitry 215. In certain alternativeembodiments, UE 200 may not include a discrete radio front-end circuitry210, rather processing circuitry 215 may instead be connected to antenna205 without radio front-end circuitry 210.

Processing circuitry 215 may include one or more of radio frequency (RF)transceiver circuitry, baseband processing circuitry, and applicationprocessing circuitry. In some embodiments, the RF transceiver circuitry,baseband processing circuitry, and application processing circuitry maybe on separate microchips or sets of chips. In alternative embodiments,part or all, of the baseband processing circuitry and applicationprocessing circuitry may be combined into one microchip or set of chips,and the RF transceiver circuitry may be on a separate microchip or setof chips. In still alternative embodiments, part or all of the RFtransceiver circuitry and baseband processing circuitry may be on thesame microchip or set of chips, and the application processing circuitrymay be on a separate microchip or set of chips. In yet other alternativeembodiments, part, or all, of the RF transceiver circuitry, basebandprocessing circuitry, and application processing circuitry may becombined in the same microchip or set of chips. Processing circuitry 215may include, for example, one or more central processing units (CPUs),one or more microprocessors, one or more application specific integratedcircuits (ASICs), and/or one or more field programmable gate arrays(FPGAs).

In particular embodiments, some or all of the functionality describedherein as being provided by a wireless device may be provided byprocessing circuitry 215 executing instructions stored oncomputer-readable storage medium 230. In alternative embodiments, someor all of the functionality may be provided by processing circuitry 215without executing instructions stored on a computer-readable medium,such as in a hard-wired manner. In any of those particular embodiments,whether executing instructions stored on a computer-readable storagemedium or not, processing circuitry 215 can be said to be configured toperform the described functionality. The benefits provided by suchfunctionality are not limited to processing circuitry 215 alone or toother components of UE 200, but are enjoyed by UE 200 as a whole, and/orby end users and the wireless network generally.

Antenna 205, radio front-end circuitry 210, and/or processing circuitry215 may be configured to perform any receiving operations describedherein as being performed by a wireless device. Any information, dataand/or signals may be received from a network node and/or anotherwireless device.

Processing circuitry 215 may be configured to perform any determiningoperations described herein as being performed by a wireless device.Determining as performed by processing circuitry 215 may includeprocessing information obtained by processing circuitry 215 by, forexample, converting the obtained information into other information,comparing the obtained information or converted information toinformation stored in the wireless device, and/or performing one or moreoperations based on the obtained information or converted information,and as a result of said processing making a determination.

Antenna 205, radio front-end circuitry 210, and/or processing circuitry215 may be configured to perform any transmitting operations describedherein as being performed by a wireless device. Any information, dataand/or signals may be transmitted to a network node and/or anotherwireless device.

Computer-readable storage medium 230 is generally operable to storeinstructions, such as a computer program, software, an applicationincluding one or more of logic, rules, code, tables, etc. and/or otherinstructions capable of being executed by a processor. Examples ofcomputer-readable storage medium 230 include computer memory (forexample, Random Access Memory (RAM) or Read Only Memory (ROM)), massstorage media (for example, a hard disk), removable storage media (forexample, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory computer-readable and/orcomputer-executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 215. In someembodiments, processing circuitry 215 and computer-readable storagemedium 230 may be considered to be integrated.

UE 200 includes input interface 220. Input interface 220 may comprisedevices and circuits configured to allow input of information into UE200 (e.g., from a user). Input interface 220 is connected to processingcircuitry 215 to allow processing circuitry 215 to process the inputinformation. For example, input interfaces 220 may include a microphone,a proximity or other sensor, keys/buttons, a touch display, one or morecameras, a USB port, or other input elements.

Output interface 225 may include devices and circuits configured toallow output of information from UE 200 (e.g., to a user). Outputinterface 225 is connected to processing circuitry 215 to allowprocessing circuitry 215 to output information from UE 200. For example,output interface 225 may include a speaker, a display, vibratingcircuitry, a USB port, a headphone interface, or other output elements.In some embodiments, the same component may function as both an inputand output interface. For example, a touch screen may output images andaccept user touches as input. Using one or more input and outputinterfaces, devices, and circuits, UE 200 may communicate with end usersand/or the wireless network, and allow them to benefit from thefunctionality described herein.

UE 200 includes power source 235. Power source 235 may comprise powermanagement circuitry. Power source 235 may receive power from a powersupply, which may either be comprised in, or be external to, powersource 235. For example, UE 200 may comprise a power supply in the formof a battery or battery pack which is connected to, or integrated in,power source 235. Other types of power sources, such as photovoltaicdevices, may also be used. As a further example, UE 200 may beconnectable to an external power supply (such as an electricity outlet)via an input circuitry or interface such as an electrical cable, wherebythe external power supply supplies power to power source 235. Powersource 235 may be connected to those components of UE 200 that needpower such as radio front-end circuitry 210, processing circuitry 215,input interface 220, output interface 225 and/or computer-readablestorage medium 230 and be configured to supply UE 200, includingprocessing circuitry 215, with power for performing the functionalitydescribed herein.

Alternative embodiments of UE 200 may include additional componentsbeyond those shown in FIG. 2 that may be responsible for providingcertain aspects of the UE's functionality, including any of thefunctionality described herein and/or any functionality necessary tosupport the solutions, features and/or benefits described herein. UE 200may also include multiple sets of processing circuitry 215,computer-readable storage medium 230, radio circuitry 210, and/orantenna 205 for different wireless technologies integrated into wirelessdevice 200, such as, for example, GSM, WCDMA, LTE, NR, WiFi, orBluetooth wireless technologies. These wireless technologies may beintegrated into the same or different chipsets and other componentswithin wireless device 200.

FIG. 6 is a flow chart illustrating a method for dynamic link selectionaccording to particular embodiments. For simplicity, the method includessteps performed by both a WD and a network node. In practice, a singledevice may only perform those steps relevant to the type of device. Forexample, a WD may select multiple links to send data, but a network nodemay determine whether received data is duplicative of other previouslyreceived data. While the corresponding description may describe ormention a particular device, it is not required that the discusseddevice perform the described step. For example, while the link selectionis being performed by a wireless device sending data to a network node,a similar method may be used for data being sent to the wireless device.Similarly, as another example, a network node may function as a relaynode and perform similar link selection with respect to forwarding ondata as is described as being performed by a wireless device. Inaddition, although the depicted method involves a UE selecting thewireless link(s) to use for transmission, the selection decision canalso be made by a network node before the WD transmits or a network nodemay make the selection and send commands to the wireless device. Thecommand can be on physical, MAC, PDCP or RRC layer.

The method starts at step 600, at step 605 a WD establishes multiplewireless links. These wireless links may be provided by one or morenetwork nodes. At least of the wireless links may be associated withdifferent radio access technologies (RATs). While the RATs may bedifferent, in some scenarios the network node may be the same. Forexample, an MSR may provide two different RATs with which the WD hasestablished two different wireless links. Although step 605 showsmultiple links being established, it is not required that the links beestablished at the same time, though they may be con-currently active.In some embodiments, as part of establishing a wireless link with amaster network node, the master network node may configure whether ornot the WD is allowed to use link diversity, what method of RRCdiversity to use, and/or what criteria to use when selecting links.

At step 610 the WD obtains data that is to be sent to a first networknode. The first network node may be associated with a first RAT and mayprovide at least one of the wireless links established with the WD. Insome embodiments, the data to be sent may be control data associatedwith the first RAT. In some embodiments, the data may comprise RadioResource Control (RRC) messages. In some embodiments, the data may beuser plane data. In some embodiments the data may be control dataassociated with a second RAT.

At step 615 the WD evaluates the link quality associated with each ofthe multiple wireless links. The link quality may be evaluated based onmeasurements, measurement reports, or any other network parameterindicating delay or channel quality. For example, the link quality whichmay be used as a parameter for link selection and mapping can be basedon reference signal received power (RSRP), reference signal receivedquality (RSRQ) or signal to interference and noise ratio (SINR)measurements. It could also be based on other parameters such asmeasured channel quality indicator (CQI) values or modulation and codingscheme (MCS) used in the uplink. In some embodiments, MCS history may beused to evaluate link quality. In another embodiment, link quality maybe evaluated based on lower layer feedback on the delivery of a message.In some embodiments, the history of the respective parameters may beused. For example, the average value of a measurement may be used.

In certain embodiments, the delay or latency of the wireless links maybe considered. Delay can be estimated either based on PDCP level delay(e.g., how long the packets are in the PDCP queue on average) or byestimating the lower layer protocol delay (e.g., the delay of RLC and/orMAC layer). RLC layer delay may include queuing in the RLC bufferwhereas MAC layer delay may include hybrid automatic repeat request(HARQ) delay as well as delay to send scheduling requests. In someembodiments, delay may correspond to HARQ delay which can be calculatedas a product of HARQ round trip time (RTT) and the number of HARQtransmissions for the MAC PDU. In one embodiment, the link with thelower delay is selected for the transmission of the control information.

At step 620 the WD evaluates the buffer status associated with each ofthe multiple wireless links. For example, if the split is on the PDCPlevel, the WD may estimate the available data in the lower layerbuffers. In some embodiments, buffer status may be evaluated from bufferstatus reports associated with each of the available wireless links.

Although not illustrated, in some embodiments, the WD may evaluate theRRC message type associated with the data that is to be transmitted.

At step 625 the WD selects one or more of the multiple wireless links touse to transmit the data. The selected wireless links may include atleast a second wireless link associated with a second RAT. In theillustrated method, the link may be selected based on the two selectionparameters evaluated at steps 615 and 620. Other embodiments may usemore, fewer, or different selection parameters. For example, oneembodiment may combine the signal strength, delay and/or buffer statusto make the link selection (e.g., a link is selected if the(estimated/measured/reported) signal strength is over the threshold andthe estimated transmission delay and/or the buffer is smaller than inanother link). In the calculation of the delay or signal strength, therecan be an averaging period over which the samples are taken. Theaveraging period or the number of samples can be configured by thenetwork node. In some embodiments, the WD may select multiple wirelesslinks if the link quality of one or all of the wireless links are belowa threshold.

Depending on the embodiment, the selection of wireless links may be doneon a per PDCP PDU basis or on a per Radio Link Control (RLC) PDU basis.Other embodiments may make the selection based on different basis. Insome embodiments, the selection decision may be made on differentprotocol layers, such as the RRC or PDCP layers. In some embodiments,cross-layer signalling/services may be required to enable the executionof decision on a different protocol layer (e.g., an input may be neededfor a decision).

The WD may select one or more links such that control plane data is onlysent on the link which has a better signal strength or quality (relativeto another link). In some embodiments, the link selection may be suchthat control plane information is by default mapped to both/allconfigured links. In certain embodiments, an offset amount may be usedsuch that control plane information is only transmitted on a single linkif its link quality is an offset amount better than the other wirelesslinks. Similarly, a threshold quality level may be used such thatcontrol plane data is sent over a single link when it's quality is abovethe threshold quality level, and sent over multiple wireless links if itis below the threshold quality level. In some embodiments, multiplelinks may be selected if the signal quality of all the available linksare below a threshold amount. In certain embodiments, a wireless linkmay be removed from consideration for use in transmitting control dataif its signal quality is below a minimum threshold. In some embodiments,if radio link failure (RLF) is expected, then the wireless link that isexpected to fail may not be used or may only be used in conjunction witha secondary wireless link. Expected RLF is determined based ontraditional criteria for predicting RLF (e.g., timers T310 and countersN310, N311 configured with different values).

At step 630 the method may diverge depending on whether the WD selectedmultiple links to use to transmit the data or only a single link.

At step 635 the WD forwards the data to be transmitted to a lower layerlink (e.g., the PDCP PDU containing the data may be forwarded to a lowerlayer link). In some embodiments, when RRC diversity is activated, PDCPPDUs are forwarded either to one lower layer link (i.e., RLC/MAC entity)or both lower layer links by means of the dynamic link selection appliedper RRC PDU/SDU or PDCP PDU basis.

At step 640, if the WD selected multiple links, the WD replicates thedata so that it can be sent via the multiple wireless links. If thesplit is at the PDCP layer, replicating the data can be done by copyingthe PDCP PDU and forwarding it on to be sent out over the multiplewireless links. In this solution, the same PDCP sequence number is usedin both links. If the split is made at the RRC level, the RRC PDU/SDU iscopied and sent over the multiple wireless links. Although the data maybe replicated, certain aspects of the transmission may be unique. Forexample, the headers may differ between the different transmissions.

At step 645 the data is transmitted to the first network node via theselected wireless links. If the WD selected multiple links, then thedata is transmitted via the multiple links using the different RATs. Ifthe WD selected only a single link, then the data is transmitted via theselected wireless link. Because the selected wireless link, or links,include at least the second wireless link, the data associated with thefirst RAT is transmitted via the second wireless link associated withthe second RAT. In some embodiments where the data being transmitted iscontrol data, the control data needed for the first wireless link may betransmitted via the second wireless link. Put another way in a specificexample, LTE control data may be transmitted via a WiMax wireless link.In some embodiments, the data to be transmitted may be control planedata. Transmitting the control data may comprise forwarding a PDCP PDUto a respective lower layer link. In some embodiments the data may beuser plane data.

At step 650 the method may diverge depending on whether or not thenetwork node needs to forward the data on to another network node. Ifthe data received by the network node is addressed to a second networknode, the network node transmits the data to the second network node atstep 670.

At step 655 the method may diverge depending on whether or not the datareceived by the network node is duplicate data.

At step 660, if the data does not need to be forwarded and it is notduplicate data, the network node may process the data in a customaryfashion.

At step 665, if the data is duplicative, the network node may discardthe duplicate data. In other embodiments, not illustrated herein, theduplicate data may be combined to reduce reception errors. In someembodiments, when the network node receives the data, either the firsttime or subsequently, the network node may inform the WD that the datahas been received by sending the transaction identifier or the PDCP SNof the received data to the WD. If the split is at the RRC level, thenetwork node can identify and discard the duplicate data based on thetransaction identifier of the RRC message.

In some embodiments, for downlink messages the network node or WD maydeduce that the data has been received correctly by the WD based onlower layer feedback. In the network node case, the network node mayinform the other network node that it can remove the control planeinformation of the given PDCP PDU or the RRC PDU/SDU. This may beachieved with existing flow control information over X2* interface (see36.423). In the uplink, the WD could be ordered to send copies of PDCPPDUs already transmitted on one link on another link if it receives agrant and it does not have data in the buffer which maps to the grantand has not yet been transmitted. This could minimize paddingtransmission. The method ends at step 675.

The steps described above are merely illustrative of certainembodiments. It is not required that all embodiments incorporate all thesteps above nor that the steps be performed in the exact order depictedin FIG. 6. For example, in some embodiments, the WD may evaluate linkquality prior to obtaining data to reduce any delay between when the WDobtains the data and transmits the data. Furthermore, some embodimentsmay include steps not illustrated in FIG. 6, such as those discussedabove.

The steps illustrated in FIG. 6, and described above, may be performedthrough a computer program product that may, for example, be executed bythe components and equipment illustrated in FIG. 1. For example, storage123 may comprise computer readable media on which a computer program canbe stored. The computer program may include instructions which causeprocessor 122 (and any operatively coupled entities and devices, such asinterface 121 and storage 123) to execute methods according toembodiments described herein. The computer program and/or computerprogram product may thus provide means for performing any steps hereindisclosed.

FIG. 7 is a block diagram illustrating the functional modules used indynamic link selection, according to particular embodiments. Inparticular, there is depicted the functional modules of a particularwireless device 700. As illustrated, WD 700 comprises obtain unit 710,selection unit 720, transmit unit 730, and replicator unit 740. Otherembodiments may include more, fewer, or different functional units.Moreover, a single depicted unit may represent multiple similar units.In general terms, each functional unit depicted therein may beimplemented in hardware and/or in software. Preferably, one or more orall functional units may be implemented by processor 112, possibly incooperation with storage 113. Processor 112 and storage 113 may thus bearranged to allow processor 112 to fetch instructions from storage 113and execute the fetched instructions to allow the respective functionalunit to perform any steps or functions disclosed herein. The illustratedunits may further be configured to perform other functions or steps notexplicitly described with respect to the respective unit, includingproviding any features or functions disclosed with respect to any of theother figures.

Obtain unit 710 is configured to obtain data to be sent to a networknode. In some embodiments, the data that is to be sent may be controldata or control plane data. The control data may be related to a firstwireless link. The first wireless link may be one of at least twoavailable wireless links. The available wireless links may be using atleast two different RATs (e.g., 3G and 4G RATs). For purposes ofdiscussion, it may be assumed that the first wireless link is associatedwith a first radio access technology. In some embodiments, the data thatis obtained by obtain unit 710 may be one or more RRC messages.

Selection unit 720 is configured to select one or more wireless links touse for the transmission of the data to be sent to the network node. Theone or more wireless links are selected from a group of at least twoavailable wireless links. The at least two available wireless links areassociated with at least two different radio access technologies. Insome embodiments, selection unit 720 may evaluate the link qualityassociated with each of the available wireless links. The relative linkquality may be used in selecting which wireless link or links to use totransmit the data. In some embodiments, selection unit 720 may evaluatethe buffer status associated with each of the available wireless links.The relative status of each available wireless link's buffer may be usedin selecting which wireless link or links to use to transmit the data.

Transmit unit 730 is configured to transmit the data to the network nodevia the selected one or more wireless links. In some embodiments,transmit unit 730 may transmit control data for the first wireless linkassociated with the first RAT via a second wireless link associated witha different RAT. In those embodiments in which selection unit 720selects multiple wireless links, transmit unit 730 may transmit thereplicated to the network node via the multiple selected wireless links.This may allow the at least two selected wireless links to convey thesame data via different radio access technologies. Where the data istransmitted via multiple wireless links, it may be the case that one ormore of the wireless links will be to a network node other than theintended recipient of the data. This node may then forward the data tothe intended network node. In some embodiments, the WD may be configuredsuch that selection unit 720 selects the wireless links, and transmitunit 730 transmits the data via the selected wireless links on a perPDCP PDU basis or a per RLC PDU basis. In some embodiments, transmitunit 730 may be configured to forward a PDCP PDU to a respective lowerlayer link.

Replicator unit 740 is configured to replicate the data to betransmitted. The data may be replicated when the selection unit 720selects more than one wireless link to use to transmit the data. In someembodiments, replicating the data may comprise making an identical, ornear identical, copy of the data and then creating separate formattingand header information for the respective wireless links.

Certain aspects of the inventive concept have mainly been describedabove with reference to a few embodiments. However, as is readilyappreciated by a person skilled in the art, embodiments other than theones disclosed above are equally possible and within the scope of theinventive concept, as defined by the appended claims. Similarly, while anumber of different combinations of features and components have beendiscussed, all possible combinations have not been disclosed. Oneskilled in the art would appreciate that other combinations exist andare within the scope of the inventive concept. Moreover, as isunderstood by the skilled person, the herein disclosed embodiments areas such applicable also to other standards and communication systems andany feature from a particular figure disclosed in connection with otherfeatures may be applicable to any other figure and or combined withdifferent features.

1. A method for dynamic link selection comprising: establishing at leasttwo wireless links; obtaining control data associated with a firstwireless link of the at least two wireless links, the first wirelesslink associated with a first radio access technology; selecting one ormore of the two wireless links to transmit the control data wherein atleast one of the selected one or more wireless links is associated witha second radio access technology; transmitting the control data to anetwork node via the selected one or more wireless links wherein thecontrol data associated with the first wireless link associated with thefirst radio access technology is transmitted via at least the secondwireless link associated with the second radio access technology.
 2. Themethod of claim 1, further comprising transmitting the control data tothe network node via at least two selected wireless links, the at leasttwo selected wireless links conveying the same control data viadifferent radio access technologies.
 3. The method of claim 1, whereinselecting one or more of the two wireless links to use for thetransmission of the control data comprises evaluating a link qualityassociated with each of the wireless links.
 4. The method of claim 1,wherein selecting one or more of the two wireless links to use for thetransmission of the control data comprises evaluating buffer statusassociated with each of the wireless links of the group of at least twoavailable wireless links.
 5. The method of claim 1 wherein transmittingthe control data comprises, for each selected wireless link, forwardinga Packet Data Convergence Protocol (PDCP) Protocol Data Unit (PDU) to arespective lower layer link.
 6. The method of claim 1, wherein selectingthe one or more wireless links is done on a per Packet Data ConvergenceProtocol (PDCP) Protocol Data Unit (PDU) basis.
 7. The method of claim1, wherein the control data comprises Radio Resource Control (RRC)messages.
 8. A wireless device for dynamic link selection comprising: awireless interface configured to: establish at least two wireless links;obtain control data associated with a first wireless link of the atleast two wireless links, the first wireless link associated with afirst radio access technology; processing circuitry configured to selectone or more of the two wireless links to transmit the control datawherein at least one of the selected one or more wireless links isassociated with a second radio access technology; wherein the wirelessinterface is further configured to transmit the control data to anetwork node via the selected one or more wireless links wherein thecontrol data associated with the first wireless link associated with thefirst radio access technology is transmitted via at least the secondwireless link associated with the second radio access technology; a userinterface; and a power source configured to provide the wireless devicewith power.
 9. The wireless device of claim 8, wherein the processingcircuitry is configured to transmit the control data to the network nodevia at least two selected wireless links, the at least two selectedwireless links conveying the same control data via different radioaccess technologies.
 10. The wireless device of claim 8, wherein theprocessing circuitry configured to select one or more of the twowireless links to use for the transmission of the control data, isfurther configured to evaluate a link quality associated with each ofthe wireless links.
 11. The wireless device of claim 8, wherein theprocessing circuitry configured to select one or more of the twowireless links to use for the transmission of the control data, isfurther configured to evaluate buffer status associated with each of thewireless links of the group of at least two available wireless links.12. The wireless device of claim 8 wherein the wireless interfaceconfigured to transmit the control data is further configured, for eachselected wireless link, to forward a Packet Data Convergence Protocol(PDCP) Protocol Data Unit (PDU) to a respective lower layer link. 13.The wireless device of claim 8, wherein the processing circuitry isconfigured to select the one or more wireless links on a per Packet DataConvergence Protocol (PDCP) Protocol Data Unit (PDU) basis.
 14. Thewireless device of claim 8, wherein the control data comprises RadioResource Control (RRC) messages.